Stress Turns on the Heat: Regulation of Mitochondrial Biogenesis and UCP1 by ROS in Adipocytes

Affiliations

1 a Department of Nutrition and Integrative Physiology and Division of Endocrinology , Metabolism and Diabetes and Program in Molecular Medicine, University of Utah School of Medicine , Salt Lake City , Utah , USA.

Authors

Affiliations

1 a Department of Nutrition and Integrative Physiology and Division of Endocrinology , Metabolism and Diabetes and Program in Molecular Medicine, University of Utah School of Medicine , Salt Lake City , Utah , USA.

Abstract

Reactive oxygen species (ROS) production and oxidative stress (OS) in adipose tissue are associated with obesity and insulin resistance (IR). The nature of this relationship i.e., cause and effect or consequence has not been clearly determined. We provide evidence that elevated mitochondrial ROS generated by adipocytes from mice with diet-induced obesity (DIO) represents an adaptive mechanism that precipitates fatty acid oxidation, mitochondrial biogenesis, and mitochondrial uncoupling in an effort to defend against weight gain. Consistent with that, mice with adipocyte-specific deletion of manganese superoxide dismutase (MnSOD) exhibit increased adipocyte superoxide generation and are protected from weight gain and insulin resistance which otherwise develops in wild-type (WT) mice that consume an obesogenic diet. The defense mechanism displayed by MnSOD-deficiency in fat cells appears to be mediated by a dual effect of ROS on inefficient substrate oxidation through uncoupling of oxidative phosphorylation and enhanced mitochondrial biogenesis. The aim of this commentary is to summarize and contextualize additional evidence supporting the importance of mitochondrial ROS in the regulation of mitochondrial biogenesis and the modulation of uncoupling protein 1 (UCP1) expression and activation in both white and brown adipocytes.

Figures

Figure 1.

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Schematic diagram of the effects…

Figure 1.

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Schematic diagram of the effects of MnSOD deletion in adipocytes. The free fatty…

Figure 1.

Schematic diagram of the effects of MnSOD deletion in adipocytes. The free fatty acids (FFA) released after lipolysis are oxidized in the mitochondria through an inefficient process involving active UCP1. The inefficient FA oxidation is supported by ROS-mediated transcriptional regulation of mitochondrial biogenesis and UCP1 expression.